Recent Publications relevant to
 East Anglian Earth Science
 (other than those in our Bulletin)

The following list of publications is not necessarily comprehensive; it represents those that have recently caught the eye of members of the Society

A seasonally ‘dry’ interglacial climate in eastern England during the early Middle Pleistocene: palaeopedolgical and stable isotope evidence from Pakefield, UK.
Ian Candy, James Rose, and Jonathon Lee, Boreas 35 (2006), pp 255-265

The Cromerian deposits, organic silts and clays, at Pakefield contain carbonate nodules (calcrete). These must have formed soon after the beds accumulated because the succeeding Unio bed truncates the horizons of carbonate nodules and some reworked nodules of it occur within the gravel lag at the base of the Unio bed.
No such large nodules are found in modern British soils. However they are found in soils where there is sufficient precipitation to dissolve and mobilise carbonate but not so much that it is leached from the soil. Such conditions occur where annual precipitation is >100 mm but not >800 mm.

The oxygen and carbon isotopic compositions of the soil carbonates were used as indicators of the environmental conditions. The two stable isotopes of oxygen, 16O and 8O, when incorporated into water control its vapour pressure, the ‘lighter’ water evaporating more readily; thus in a different climate different levels of precipitation and evaporation would effect the oxygen isotope composition of included carbonates. Thus the δ 18O composition of the carbonate reflects the isotopic composition of the source water, which will in turn is controlled by temperature and evaporation. The two stable isotopes of carbon, 12C and 13C, are absorbed to different extents by vegetation; thus the δ 13C composition of the carbonate reflects the composition of the overlying vegetation assemblage. The 18O levels of the Pakefield nodules are indeed unusually high, indicating either a ‘heavier’ isotopic composition of rainfall because of higher air temperatures and/or intense evaporation of soil moisture during calcrete formation. The δ 13C levels of the Pakefield nodules indicate carbonate precipitation under full interglacial vegetation
Although the current rainfall at Pakefield falls within the range required for nodules to form (ca. 580 mm) it is comparatively uniform throughout the year, sufficiently so as to be unfavorable for calcrete formation; a more uneven rainfall distribution is required with evopotranspiration considerably exceeding precipitation, at least at certain times.
The presence of tree pollen from oak, pine, and elm, indicates that total annual precipitation levels were probably similar to those of today, and the presence of water chestnut and floating water fern shows that perennial bodies of water existed. Thus it can be concluded that precipitation was very uneven with dry periods during which the calcrete formed, but with sufficient precipitation at other times to maintain aquifers sufficient to allow the vegetation and water bodies to be maintained.
Modern Europe has two regimes with such marked rainfall seasonality – central and eastern Europe, with warm wet summers and dry cold winters, and southern Europe with cool wet winters and hot dry summers. Since the remains of Hippopotamus amphibus have been found at Pakefield the latter regime is obviously favored! Thus it seems that there is strong evidence for a Mediterranean type climate within the Cromerian interglacials.
Although we have no reason to ascribe this to high levels of carbon dioxide we might justifiably regard this as a prediction of the climatic regime that will dominate as levels of CO2 increase in our climate in the near future.
This reviewer noted that although the authors attempted to describe the location of all Cromerian sites in England they did not mention Norton Subcourse. This is presumably the result of there being no publication of the results of research at that site in a peer-reviewed journal.

ET

The book “ When Life Nearly Died. The greatest mass extinction of all time ”. Michael J Benton, Thames & Hudson, 2003 .

and the paper “ How to kill (almost) all life: the end-Permian extinction event”. Trends in Ecology & Evolution 18 , July 2003, M J Benton & R J Twitchett.

At depth beneath Norfolk there are only a few rocks of Permian age; at that time Norfolk was on the northern edge of the London-Brabant Massif. Lystrasaurus probably walked here! However it has long been recognised that there was a major global extinction event at the end of the Permian, now known to be at 251 Ma. This subject interests many Earth Scientists but in this country Dr Wignall ( Univ. of Leeds ) and Prof. Benton ( Univ. of Bristol ) have been pre-eminent.

Prof. Benton has obviously put a lot of scholarship into an excellent book that is very readable. The author recognises that nothing in science is immutable and professes himself unconcerned if his book eventually finishes up discredited and collecting dust; but for the time being he advances interpretations by himself and other workers that add up to a coherent consistent picture. In the book the reader is introduced into each topic from an historical perspective and it is easy to appreciate how advances in Earth Science have been made, and with Prof Benton's explanations no pre-existing really specialised knowledge is needed. This makes it attractive to the scientifically literate general reader.

At one time the extinction was thought to be a gradual process over as much as 10 million years that mainly took place in the seas but recent research and modern techniques have shown that it was much more sudden in geological terms and occurred everywhere. As much as 95% of all species on Earth were lost! This makes it the most catastrophic event known, far worse that that wiped out the dinosaurs at the end of the Cretaceous.

Life had had it good during the Carboniferous and most of the Permian. Oxygen levels in the atmosphere had reached an all-time high, vast coal-generating forests had clothed the Pangaean Continent and the seas were teeming with life. But it seems that at the end of the Permian there was a catastrophe. Some workers profess to have found evidence of an asteroid impact but others contest the data. Instead Prof. Benton finds the likely impact of the gaseous emissions from the basaltic lavas of the Siberian Traps a more like likely culprit. By extrapolating from similar eruptions in places like Iceland it is possible to calculate the amount of sulfur dioxide and carbon dioxide that would have been emitted. In such eruptions the SO 2 (and other acid gases) usually has little effect (except locally) since it is quickly washed out of the atmosphere by rain, but even the comparatively small Icelandic eruptions have emitted sufficient CO 2 to disturb the climate of the northern hemisphere to a discernable degree for a few years. New evidence about the rapidity of the Siberian eruptions (over just 600,000 yrs) just at the Permo-Triassic boundary indicate that the planet's biomass would have been considerably stressed. Normal compensatory feedback mechanisms could not compensate sufficiently. Shortly after there was a marked change in the carbon isotope ratios indicating release of considerable amounts of 12 C in quantities greater than can be explained by decomposition of the biosphere; and the only credible source is methane hydrates. Changes in oxygen isotope ratios are consistent with a subsequent 6 o C temperature rise resulting from the exaggerated greenhouse effect. Even if you are suspicious of catastrophes this book is well worth reading. What a great subject. Highly recommended.

For those who don't need the techniques explaining, Prof. Benton has written the paper that contains the essence of the book.

Bowen et al., (2002), Quaternary Science Reviews 21 89-101 New data for the Last Glacial Maximum in Great Britain and Ireland

Brand, Booth, & Rose (2002), Proceedings of the Yorkshire Geological Society, 54, 35-46. Late Devensian glaciation, ice-dammed lake and river diversion, Stiffkey, north Norfolk, England.

Candy, (2002), Proc. Geol. Assoc., 113, 259-270 Formation of a rhizogenic calcrete during a glacial stage (OIS 12): its palaeoenvironmental and stratigraphic significance,

Keene, (2001), Quaternary Science Reviews 20 1657-1665 Towards a late middle Pleistocene non-marine molluscan biostratigraphy for the British Isles,

Lee, (2001) Proc. Geol. Assoc. 112, pp 29-44, Genesis and palaeogeogrphical significance of the Corton Diamicton (basal member of the North Sea Drift Foramtion), East Anglia, UK

The Corton Diamicton, the lower diamicton unit of the Anglian-age North Sea Drift Formation is investigated at two coastal localities in East Anglia - Trimingham and Corton. At Trimingham, the diamicton was deposited subglacially by Scandinavian ice that entered the region of north Norfolk from the northeast. The deposit consists of a three-tiered till assemblage characteristic of constructional glaciotectonic deformation: a lower tectonite consisting of deformed local preglacial sands; a middle till deformed by brittle shear; and an upper massive till deformed by ductile deformation. At Corton, the diamicton was deposited as part of a prograding grounding line fan which formed as a point-source depocentre adjacent to the temporary, subaqueous grounded margin of the Scandinavian ice sheet. The study contributes to an understanding of early Anglian palaeogeography by demonstrating the influence of grounded ice on drainage within the Bytham catchment, and the development of an extensive proglacial lake basin within the region.

Lee, Rose, Riding, Moorlock, & Hamblin, (2002), Boreas, Vol. 31, pp 345-355.Testing the case for a Middle Pleistocene glaciation in Eastern England: evidence for a Scottish ice source for tills within the Corton Formation of East Anglia, UK. J

The provenance of the Happisburgh Till and Corton Till of the Corton Formation is investigated using erratic clast lithologies and allochthonous palynomorphs to test whether the long held assumption that they were deposited by ice that originated in Scandinavia is valid. The results show a wide range of lithologies including Carboniferous Limestone and Coal Measures, and Permian Magnesian Limestone that are not found in Scandinavia, and an absence of distinctive Scandinavian material such as rhomb porphyry and larvikite. Lithologies found indicate deposition by an ice sheet that flowed southwards into northeast East Anglia from central and southern Scotland eroding and transporting materials derived from outcrops in these areas and from eastern England and the western margins of the southern North Sea Basin. It is concluded that the long held assumption that a Scandinavian ice sheet deposited the Happisburgh Till and Corton Till of the Corton Formation is erroneous and that they were instead deposited by Scottish ice.

Machetel & Thomassot, (2002), Earth & Planetary Science Letters 202, pp 379-386
Cretaceous length of day perturbation by mantle avalanche

It is now well known that the Cretaceous Chalk of Norfolk was deposited under rather extreme conditions, namely high sea level, high ambient temperatures, and high atmospheric CO2. To explain this it has been proposed that at least this once during Earth history there was an episode of very intense volcanic activity caused by a superplume, a large stream of overheated (and thus relatively light) material rising buoyantly from the D" layer at the base of the mantle that derived its heat from the core. This plume spread laterally at the base of the lithosphere to affect an area ten times larger than that covered by more normal plumes, such as those under Hawaii, Iceland, and Yellowstone today. One result was the creation of numerous chains of seamounts and ocean plateaux in the western Pacific at a rate some five times greater during this period than at other times. At the same time, at 120-125Ma, the rate of formation of oceanic crust almost doubled over a period of 5 Ma, decreased within the next 40-50 Ma, and returned to previous levels about 80 Ma ago.

Coupled with the increased production of crust, and caused by the consequent general rise in the level of the sea floor, there was a worldwide increase in sea level to an elevation some 250 m higher than at the present day. As shown by oxygen isotope measurements made on benthic foraminifera from the North Pacific, the surface temperature of the Earth also increased by about 10oC. This effect was probably caused by the release of large amounts of carbon dioxide during the volcanic eruptions, with a resulting enhanced 'greenhouse' effect. During the superplume episode the rates of carbon and carbonate sequestration in organisms (and hence deposition of the chalk!) increased in the extensive warm (up to 32oC) shallow seas produced by flooding of the continental margins. Immediately after the rate of geomagnetic reversals was very low, with the Earth’s magnetic field remaining in normal polarity for as long as 40 Ma (compare this with 0.78 Ma so far for the present chron). This indicates that activity in the core, where the geomagnetic field originates, was low, perhaps related to the transfer of considerable quantities of heat to the mantle.

What was the cause of this superplume? Obviously, if there was a massive up-welling of magma from the mantle, there must equally have been a balancing descent of material of some kind. It is postulated that this descent was an “avalanche” of part of the lithosphere and the upper mantle into the lower mantle down to the core, accelerated by the endothermic phase change from silicate spinel to perovskite & magnesiowustite, at 670 Km depth. The resulting transfer of relatively dense material into the Earth’s interior would have changed the rotational moment of inertia of the Earth, speeding up the rotation rate in a manner similar to that experienced by a pirouetting skater when she pulls in her arms.

Machetel & Thomassot draw our attention to the evidence for results of studies of simultaneous seasonal fluctuations of coral growth and their daily growth increments combined with tidally controlled growth patterns exhibited by fossil molluscs; this evidence indicates an acceleration of the Earth’s rotation rate between 220Ma and 80Ma leading to a reduction in the length of the day. There is also evidence for a change in another component of the Earth’s rotation, namely a strong True Polar Wander event (not the same thing as a magnetic reversal!) during the period 180 Ma to 80 Ma.

The authors report that solution of a numerical model of the process has confirmed the quantitative feasibility of the proposal.

When reviewing this paper this reviewer [ET] found Global Tectonics, by Kearley & Vine (the latter of University of East Anglia), Blackwell Science, 2nd Edition 1996, to be an invaluable reference source. Also email communication with Dr Machetel resolved certain issues about the quality of the evidence for change in day length.

Maddy et al., (2001), Quaternary International 79 23-36, Uplift-driven valley incision and climate-controlled river terrace development in the Thames Valley, UK,

Rose, Moorlock, & Hamblin, (2001),Quaternary International, 79, pp 5-22, Pre-Anglian fluvial and coastal deposits in Eastern England: lithostratigraphy and palaeoenvironments,

Whereas previously pollen analysis and fossil content have been the favoured means of distinguishing between the various Formations and members of the East Anglian Pleistocene, we should also consider an alternative technique that is based on the rational consequences of the climate and sedimentary environment on the input to East Anglia of rock types from the Midlands, North Wales, the Pennines, and East Yorkshire

From ca. 2.6 million years ago the climate began to oscillate between extremes, from the benign and temperate to harsh and glacial. The action of ice and periglacial conditions on the uplands of England and Wales began to release into the major river systems quantities of material never seen before. This was swept down these rivers and eventually was laid down in the fluvial and marine deposits of East Anglia. Thus the Thames, which at the beginning of this time had its source in north Wales, brought down ‘erratics’ from Wales and the south Midlands, the Bytham River from the north Midlands and southern Pennines, and the Ancaster River from the Pennines and east Yorkshire. Thus the origins of the quartz, quartzite, Carboniferous chert, Jurassic (Rhaxella) chert, and Greensand chert found here can be identified, and their probable means of transport identified.

After the release of these materials into the rivers transport into marine environments obviously took time. Thus in the Norwich Crag (ca. 2.1-1.6 Ma), which is of course of marine origin, the main constituent of the gravels is flint derived from local sources such as the Red Crag, early terrace deposits of the Thames (Nettlebed Formation) and, predominately of course, the Chalk. Thus the youngest member of the Norwich Crag Formation, the Westleton Member, (1.85-1.6 Ma), was a near shore marine deposit consisting of at least 92% well rounded flints mostly chatter marked from being rolled against one another by wave action. The incidence of quartzites from the Midlands and Greensand Chert from the Weald is quite low. Only in later marine deposits (Wroxham Crag) were there increasing proportions of non-flint clasts. Thus the oldest part of the Wroxham Crag, the Dobbs member (ca.1.6-1.5 Ma) typically contains 93-78% flint, the next oldest, the How Hill member (ca.1.5-1.2 Ma), when the Bytham had become the dominant supplier of sediment, has 70-48% flint and the youngest, the Mundesley member (ca. 0.7 Ma), presumably more influenced by the input of material by the Ancaster river, also has 82-72% flint. Similarly the proportion of quartz and quartzites increased.

The compositions of the fluvial deposits can also be rationalised. As might be expected the proportion of flint in the Sudbury Formation (ca. 1.0 Ma) of the Thames catchment area was often lower (70-40%) than in marine deposits of similar age. However after the source of the Thames was displaced from N. Wales to the Cotswolds by neotectonic processes the proportion of flint in the later Colchester Formation (ca. 0.6 Ma) rose again to ca. 65-70%. The Bytham seems to have contributed a relatively low but variable proportion of flint, ca. 65-20%.

However it is by the various proportions of non-flint clasts that the fluvial deposits of the Bytham and Thames can be most readily distinguished. Thus In the Bytham River terraces Greensand chert is not found. Also the relative amounts of white/colourless quartzite + quartz and coloured quartzite + quartz are apparently diagnostic. Thus in the Sudbury Formation this seems to be about 12% for white/colourless quartzite + quartz and 5-16% for coloured quartzite + quartz. The composition of the Colchester Formation can be similar but as little as ca 1% of white/colourless quartzite + quartz with 27% coloured quartzite + quartz has been seen. For the Bytham terraces the proportion of coloured quartzite + quartz is in the range 17-70%!

This is a very readable paper that contains a lot of information and ideas not mentioned in this review, and a comprehensive list of references. Please note that the dates (Ma BP) are not quoted in the body of this paper but are deduced by this reviewer from a diagram therein.
ET

Rose et al, (2002) Proc. Geol. Assoc. 113, 47-68, Early and early Middle Pleistocene River, coastal and neotectonic processes, southeast Norfolk, England

Rose et al. have continued to refine their technique for differentiating the pre-Anglian deposits in East Anglia using clast analysis to establish a lithological signature based: -
• % flint
• Ratio of flint to quartzite + vein quartz + schorl
• Ratio of quartzite to vein quartz
• Ratio of red and brown quartzite + vein quartz to white quartzite + vein quartz
(See previous newsletter for a review of previous paper.) In this paper the authors concentrate on data from the Leet Hill pit near the Waveney Valley, the Bramerton Common pit, and two boreholes sunk at The Grange, Langley, and Hales Hall. They show that Bytham Sands and Gravels, laid down during a cold period by the Bytham River, extend from Leet Hill north to Hales Hall. However at The Grange, Langley, these are replaced by Wroxham Crag and overlain by Happisburgh Till. The Wroxham Crag continues to Bramerton where appears to overlay the Norwich Crag; in fact part of the section previously attributed to the Norwich Crag appears to be Wroxham Crag!

Three lines of evidence suggest that this region was affected by neotectonic deformation in the early Pleistocene.

• The apparent transgression of the Wroxham Crag across the Norwich Crag to a level ca. 20-25 OD at a time when global sea level was probably lowering as a result of global climatic deterioration, & when sea levels were not rising elsewhere. This suggests regional subsidence.

• The dissection of the Wroxham Crag by the Bytham Sands and Gravels, in both temperate and cold climates, when the Bytham River experienced both incision and aggradation, indicates that the land had been uplifted following the deposition of the Wroxham Crag
• The presence of Norwich Crag up to 12 m OD, at a time when sea level was rarely higher than present, also confirms that uplift had occurred in the region.

Thus it appears that there was a neotectonic subsidence in early Wroxham Crag times and subsequent uplift before incision and deposition by the Bytham River.

This is an important paper that is likely to play an important role in understanding this part of the Pleistocene. The results at Bramerton are intriguing!
ET

Stuart & Lister, (2001),Quaternary Science Reviews, 20 pp 1677-1692. The mammalian faunas of Pakefield/Kessingland and Corton, Suffolk, U.K: evidence for a new temperate episode in the British early Middle Pleistocene.

Oxygen isotope curves show that the early Middle Pleistocene (ca. 0.78-0.45 Ma, OIS stages 19-13), corresponding to the “Cromerian Complex” of the Netherlands, was a period of complex climatic changes. The mammal faunas existing during this period in Britain are currently divided into an earlier group with the remains of the extinct water vole Mimomys savini (the West Runton Freshwater Bed (WRFB), Sugworth, & Little Oakley) and a later group in which it is succeeded by Arvicola terrestris cantiana (Boxgrove, Sidestrand/Trimingham, Westbury, & Ostend in Norfolk). These sites are considered to represent two or more temperate/interglacial stages. Moreover, on the basis of the available early Middle Pleistocene non-marine molluscan faunas, Meijer and Preece (in: C. Turner (Ed.), The Early Middle Pleistocene in Europe, Balkema: Rotterdam, 1996, pp. 53-82.) and Preece (Quaternary Science Reviews 20 (2001), 1643-1656) recognised three biostratigraphic groups, representing at least three temperate stages. This subject has also been well reviewed by Preece and Parfitt in The Quaternary of Norfolk & Suffolk Field Guide, Ed. Lewis, Whiteman, & Preece, Quaternary Research Association, 2000, pp 1-28).

Stuart & Lister present evidence of new finds in the exposures in the cliffs at Pakefield & Kessingland, Suffolk, indicating an additional, hitherto unrecognised, temperate stage with Mimomys savini that is younger than the WRFB but older than Little Oakley, Boxgrove and Westbury. The large-mammal fauna from here (found in the Rootlet Bed) and from Corton, which has a similar lithostratigraphic and biostratigraphic sequence, includes Hippopotamus sp., PaIaeoloxodon antiquus (commonly known as the straight-tusked elephant), and Megaloceros dawkinsi (a species of giant deer), none of which has so far been found in the WRFB. This strongly suggests that the Suffolk sites represent a distinct stage. The plants Trapa natans (water chestnut) and Salvinia natans (floating water fern), which indicate that the summers were warmer than now, are found at both Corton & Pakefield but not at West Runton

This paper is notable for its excellent illustrations of fossils found at these sites, worth reading for them alone.

In passing this reviewer notes that the evidence for the dating of the Cromerian deposits rests to some extent on fragmented information; we should expect more research to be done.
ET

Gilian N. Thomas, (2002) Quaternary Science Reviews 21 1621-1630 Late Middle Pleistocene pollen biostratigraphy in Britain: pitfalls and possibilities in the separation of interglacial sequences,

Rob Westaway et al., (2002) Quaternary Science Reviews 21 559-603
Flow in the lower continental crust as a mechanism for the Quaternary uplift of south-east England: constraints from the Thames terrace record

Whiteman, C.A. (2002), Permafrost and Periglacial Processes, 13, 163-170. Implications of a Middle Pleistocene Ice-Wedge cast at Trimingham, Norfolk, eastern England.

A wedge exposed at Trimingham, northeast Norfolk, UK, in 1998 is interpreted as an ice-wedge pseudomorph indicating that permafrost was present in the surrounding Cromer Forest-bed Formation sediments. The North Sea Drift Formation (NSDF) glacial sediments overlie the wedge, demonstrating that the associated ice sheet deposited till in either a terrestrial or an extremely shallow glaciolacustrine/marine environment. This conclusion supports those who believe that this ice sheet was, at least initially, terrestrial at this location.